Some of the SMT tutorials on the Internet show ways of using fine-gauge rosin solder or solder paste to solder these ICs - essentially, they tell you to rely on surface tension and the natural bond of the solder to the pads, literally pulling the solder away from a shorted condition to pool on the individual pads. In fact, one tutorial I viewed shows actually laying down a "worm" of solder paste bridging all the terminals on one side of a chip and then applying heat with an embosssing gun - a scaled-down heat gun. As soon as the solder goes liquid it draws back to the pads. Might be worth trying, though I admit I chickened out when it came to trying to replace the RS-232 transceiver on my KIO3.
73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 On 8/27/2010 3:47 PM, Dave Hachadorian wrote: >>> Any ideas are welcome. Meanwhile, is the LM4950TS stereo amp >>> available as a component from Elecraft, and is it >>> user-repairable? >>> > That chip is fragile. I've blown it twice, just with excessively > loud audio. (AGC OFF) > > I'm a fairly good solderer, and I bought a replacement IC here: > http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=LM4950TS-ND > > I was able to remove the old chip by cutting all the leads, and > removing them one by one, but when I looked at the tiny pads on > the circuit board, I chickened out. I couldn't see any way to > solder those pins to the pads without shorting them to each > other. They are EXTREMELY close together. > > I ended up sending the DSP Board back to Elecraft for repair. > > Dave Hachadorian, K6LL > Big Bear Lake, CA > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > . > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
